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Note: eBird data last updated October 2024.

Survey effort: all years

This interactive map summarizes survey effort (measured in hours) logged on eBird across California in any year. By looking across all available data, these maps show which parts of the state have had better and wrose coverage. The data are summarized to show three categories of surveys:

  • Breeding season (checklists from March–August)
  • Checklists with breeding codes (checklists from any month, but with at least one probable/confirmed breeding code)
  • Winter season (checklists from December–February)

Survey effort is unevenly distributed across the state The proportion of blocks with zero survey effort in each layer is:

  • Breeding season: 25%
  • Checklists with breeding codes: 53%
  • Winter season: 45%
 




By Sam Safran